Wilfred Sellars

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Wilfred Sellars

The influential American philosopher Wilfred Sellars (1912-1989) developed a unified and novel philosophical system that had wide influence on American philosophy. Sellars was a president of the American Philosophical Association and the author of many books and articles, most notably Science, Perception and Reality and Science and Metaphysics.

Wilfred Sellars was born on May 20, 1912, in Ann Arbor, Michigan. He was the son of the American philosopher Roy Wood Sellars, who was an influential participant in the critical realist movement within the United States. He was educated at various universities in the United States and Great Britain and began his teaching career as an assistant professor at the University of Iowa in 1938. In 1947 he accepted a position at the University of Minnesota as professor of philosophy and remained there until 1958, at which time he accepted a position at Yale University. In 1963 he accepted the position of professor of philosophy at the University of Pittsburgh.

The characteristic mark of American philosophy during the middle half of the 20th century was an unwillingness to construct unified systems of thought that responded to most, if not all, the perennial questions of philosophy. American philosophers during this period fell under the influence of empiricist and linguistic assaults on traditional metaphysics and became skeptical of the very enterprise of building philosophical systems. Wilfred Sellars rejected this skeptical loss of nerve and constructed a system of ideas that originated from his solution to what he considered the primary philosophical problem of our epoch—the problem of connecting scientific with ordinary accounts of the world. He refers to these accounts as the "scientific and manifest images."

The manifest image or the common sense account of the world is, at first glance, inconsistent with the scientific account of the world since ordinary men never see neutrons or use electron microscopes. However, the manifest image is, according to Sellars, never completely abandoned by science because scientific proof requires that evidence be available to anyone and hence scientific evidence ultimately must end up appealing to the manifest image. Furthermore, the objects of science are, for Sellars, modeled on ordinary objects. These two domains are separate, irreducible domains but they are interconnected. Both domains are dialectically dependent on one another in the sense that we need the scientific image to validate the hypotheses of science and we need the scientific image to provide the ontology of the manifest image while the manifest image provides the epistemological foundation of the scientific image. What unites these two realms is that both are intrinsically realistic in that both domains posit the existence of realities that exist independently of our cognitive processes.

Science then must never abandon ordinary objects if it is to retain its universal status. This is because ordinary common sense postulates the existence of chairs and tables but these objects do not "explain" our sensations. This is the empiricist trap. Rather, these ordinary objects are "directly perceived" and these directly perceived objects are models for forming abstract pictures of sensations. The world of perception is a construct based on the contents of the manifest or common sense picture of the world. Furthermore, believing in ordinary objects, such as chairs and tables, is, for Sellars, not a synthetic or casual belief. It is an analytic belief in the sense that the meaning of our most basic scientific terms, such as sensation or perception, assume these ordinary objects as models for explaining what a sensation or perception is. The scientific image is also realistic. It postulates not ordinary objects but theoretical objects to account for our complex scientific experience. These theoretical objects are, according to Sellars, parasitic on ordinary objects in the sense that the scientist will always require ordinary objects to explain what he means by theoretical objects.

This view of science plays a crucial role within Sellars' conception of the human mind. The central theme of his picture of the mind is that the mind in both its actions (remembering, seeing, feeling, etc.) and its contents (memories, sensations, sentiments, etc.) can be interpreted neutrally without assuming that minds are either material objects or immaterial objects. He therefore rejects claims such as "the mind is the brain" as well as claims such as "the mind is a spirit." For Sellars, they might be either, but the philosophy of the human mind by itself cannot lead to either conclusion. The reason or basis for this neutralist view of the mental is that, according to Sellars, all mental events are functional. A functional event is what is minimally needed to predict the occurrence of the second event, given the occurrence of the first within the appropriate circumstances. Thus, if one takes an aspirin when one has a headache, the belief that aspirin reduces pain is functional in the sense that it connects taking aspirin with having a headache. For Sellars, functional mental events are minimal events and, since they are minimal, they must be neutral with respect to being either material or immaterial.

Sellars' ethical writings concern themselves with fitting ethical discourse within this functional, scientific realism. The heart of his moral concern is to establish that moral acts are free in the sense that they are caused by a certain type of mental event called a volition and the absence of volition to do an act X makes act X determined or accidental rather than free. Volitions are thus the functional element within morality. But while volition or freedom is at the core of the moral evaluation of persons, it is not, for Sellars, at the core of the moral evaluation of actions. Actions, he claimed, must be viewed from the viewpoint of general consequences for relevant communities. It is the general welfare of the relevant community that constitutes the realistic basis for justifying which actions ought to be freely committed. In short, Sellars' ethics is systematically unified with both his philosophy of mind and his theory of knowledge.